It's really all down to the quality of the printing and the skill of the printers. You only have to look back at high quality work from the 1960's and 70's (thinking of what was done in Switzerland, etc.) to see the quality which was produced from Kodachrome and Agfacolor at that time. Or even some of the illustrated books produced in Germany from early Agfacolor.

I guess that these skills have been lost now that everything is done on a computer screen.